Bushby et al reported an algorithm for identifying a patient with Duchenne's muscular dystrophy (DMD). The authors are members of the DMD Care Considerations Working Group and are from multiple universities in North America and Europe.
DMD is an X-linked disorder.
When to suspect DMD in a patient:
(1) male child with a family history of DMD
(2) male child not walking by 18 months of age
(3) male with unexplained increases in AST and ALT (transaminases)
(4) male with Gower's sign (the patient stands up by "walking the hands" up the legs)
(5) male with marked increase in CK
A patient meeting items 1 to 4 should have serum CK testing. A patient with DMD will have a markedly increased (10-fold) serum CK concentration.
The diagnostic steps:
(1) genetic testing for a deletion or duplication in the dystrophin gene
(2) demonstration of no or extremely low dystrophin protein in a muscle biopsy (by Immunoperoxidase stains or direct analysis)
Sequence of diagnostic steps:
(1) A patient with evidence of DMD in a muscle biopsy still needs to have genetic testing to confirm the diagnosis.
(2) A patient with evidence of DMD in genetic testing does not need a muscle biopsy for diagnosis but it may be helpful to determine disease severity.
Next steps:
(1) The patient should be referred to a specialized multidisciplinary team for management.
(2) Females in the family who may be carriers should be receive genetic counseling.
(3) The family should receive information about support groups and patient organizations that may be able to help.
